Mortality due to acute rheumatic fever and rheumatic heart disease in the Northern Territory: a preventable cause of death in aboriginal people

Outcomes of rheumatic fever in Uganda: a prospective cohort study

BACKGROUND

Rheumatic heart disease is the largest contributor to cardiac-related mortality in children worldwide. Outcomes in endemic settings after its antecedent illness, acute rheumatic fever, are not well understood. We aimed to describe 3-5 year mortality, acute rheumatic fever recurrence, changes in carditis, and correlates of mortality after acute rheumatic fever.

METHODS

We conducted a prospective cohort study of Ugandan patients aged 4-23 years who were diagnosed with definite acute rheumatic fever using the modified 2015 Jones criteria from July 1, 2017, to March 31, 2020, enrolled at three rheumatic heart disease registry sites in Uganda (in Mbarara, Mulago, or Lira), and followed up for at least 1 year after diagnosis. Patients with congenital heart disease were excluded. Patients underwent annual review, most recently in August, 2022. We calculated rates of mortality and acute rheumatic fever recurrence, tabulated changes in carditis, performed Kaplan-Meier survival analyses, and used Cox regression models to identify correlates of mortality.

FINDINGS

Data were collected between Sept 1 and Sept 30, 2022. Of 182 patients diagnosed with definite acute rheumatic fever, 156 patients were included in the analysis. Of these 156 patients (77 [49%] male and 79 (51%) female; data on ethnicity not collected), 25 (16%) died, 21 (13%) had a cardiac-related death, and 17 (11%) had recurrent acute rheumatic fever over a median of 4·3 (IQR 3·0-4·8) years. 16 (24%) of the 25 deaths occurred within 1 year. Among 131 (84%) of 156 survivors, one had carditis progression by echo. Moderate-to-severe carditis (hazard ratio 12·7 [95% CI 3·9-40·9]) and prolonged PR interval (hazard ratio 4·4 [95% CI 1·7-11·2]) at acute rheumatic fever diagnosis were associated with increased cardiac-related mortality.

INTERPRETATION

These are the first contemporary data from sub-Saharan Africa on medium-term acute rheumatic fever outcomes. Mortality rates exceeded those reported elsewhere. Most decedents already had chronic carditis at initial acute rheumatic fever diagnosis, suggesting previous undiagnosed episodes that had already compounded into rheumatic heart disease. Our data highlight the large burden of undetected acute rheumatic fever in these settings and the need for improved awareness of and diagnostics for acute rheumatic fever to allow earlier detection.

FUNDING

Strauss Award at Cincinnati Children's Hospital, American Heart Association, and Wellcome Trust.

Rheumatic heart disease mortality in Indigenous and non-Indigenous Australians between 2010 and 2017

OBJECTIVES

To generate contemporary age-specific mortality rates for Indigenous and non-Indigenous Australians aged <65 years who died from rheumatic heart disease (RHD) between 2013 and 2017, and to ascertain the underlying causes of death (COD) of a prevalent RHD cohort aged <65 years who died during the same period.

METHODS

For this retrospective, cross-sectional epidemiological study, Australian RHD deaths for 2013-2017 were investigated by first, mortality rates generated using Australian Bureau of Statistics death registrations where RHD was a coded COD, and second COD analyses of death records for a prevalent RHD cohort identified from RHD register and hospitalisations. All analyses were undertaken by Indigenous status and age group (0-24, 25-44, 45-64 years).

RESULTS

Age-specific RHD mortality rates per 100 000 were 0.32, 2.63 and 7.41 among Indigenous 0-24, 25-44 and 45-64 year olds, respectively, and the age-standardised mortality ratio (Indigenous vs non-Indigenous 0-64 year olds) was 14.0. Within the prevalent cohort who died (n=726), RHD was the underlying COD in 15.0% of all deaths, increasing to 24.6% when RHD was included as associated COD. However, other cardiovascular and non-cardiovascular conditions were the underlying COD in 34% and 43% respectively.

CONCLUSION

Premature mortality in people with RHD aged <65 years has approximately halved in Australia since 1997-2005, most notably among younger Indigenous people. Mortality rates based solely on underlying COD potentially underestimates true RHD mortality burden. Further strategies are required to reduce the high Indigenous to non-Indigenous mortality rate disparity, in addition to optimising major comorbidities that contribute to non-RHD mortality.

Group A Streptococcus Infections: Their Mechanisms, Epidemiology, and Current Scope of Vaccines

Group A streptococci (GAS) are gram-positive, cocci-shaped bacteria that cause a wide variety of infections and are a cause of significant health burden, particularly in lower- and middle-income nations. The GAS genome contains a number of virulence factors such as the M-protein, hyaluronic acid, C5a peptidase, etc. Despite its significant health burden across the globe, a proper vaccine against GAS infections is not yet available. Various candidates for an effective GAS vaccine are currently being researched. These are based on various parts of the streptococcal genome. These include candidates based on the N-terminal region of the M protein, the conserved C-terminal region of the M protein, and other parts of the streptococcal genome. The development of a vaccine against GAS infections is hampered by certain challenges, such as extensive genetic heterogeneity and high protein sequence variation. This review paper sheds light on the various virulence factors of GAS, their epidemiology, the different vaccine candidates currently being researched, and the challenges associated with M-protein and non-M-protein-based vaccines. This review also sheds light on the current scenario regarding the status of vaccine development against GAS-related infections.

What Lies Ahead for Young Hearts in the 21st Century - Is It Double Trouble of Acute Rheumatic Fever and Kawasaki Disease in Developing Countries?

Rheumatic heart disease (RHD), the principal long-term sequel of acute rheumatic fever (ARF), has been a major contributor to cardiac-related mortality in general population, especially in developing countries. With improvement in health and sanitation facilities across the globe, there has been almost a 50% reduction in mortality rate due to RHD over the last 25 years. However, recent estimates suggest that RHD still results in more than 300,000 deaths annually. In India alone, more than 100,000 deaths occur due to RHD every year (Watkins DA et al., N Engl J Med, 2017). Children and adolescents (aged below 15 years) constitute at least one-fourth of the total population in India. Besides, ARF is, for the most part, a pediatric disorder. The pediatric population, therefore, requires special consideration in developing countries to reduce the burden of RHD. In the developed world, Kawasaki disease (KD) has emerged as the most important cause of acquired heart disease in children. Mirroring global trends over the past two decades, India also has witnessed a surge in the number of cases of KD. Similarly, many regions across the globe classified as “high-risk” for ARF have witnessed an increasing trend in the incidence of KD. This translates to a double challenge faced by pediatric health care providers in improving cardiac outcomes of children affected with ARF or KD. We highlight this predicament by reviewing the incidence trends of ARF and KD over the last 50 years in ARF “high-risk” regions.

Raising awareness for rheumatic mitral valve disease

Rheumatic heart disease (RHD) is a major burden in low- to mid-income countries, where each year it accounts for over a million premature deaths associated with severe valve disease. Life-saving valve replacement procedures are not available to the majority of affected RHD patients, contributing to an increased risk of death in young adults and creating a devastating impact. In December 2017, a group of representatives of major cardiothoracic societies and industry, discussed the plight of the millions of patients who suffer from RHD. A comprehensive solution based on this global partnership was outlined in "The Cape Town Declaration on Access to Cardiac Surgery in the Developing World". The key challenge in controlling RHD is related to identification and removal of barriers to the translation of existing knowledge into policy, programs, and practice to provide high-quality care for patients with RHD. This review provides an overview on RHD by emphasizing the disease medical and economic burdens worldwide, risk factors, recent advance for early disease detection, and overall preventive strategies.

Sharing success - understanding barriers and enablers to secondary prophylaxis delivery for rheumatic fever and rheumatic heart disease

BACKGROUND

Rheumatic fever (RF) and rheumatic heart disease (RHD) cause considerable morbidity and mortality amongst Australian Aboriginal and Torres Strait Islander populations. Secondary antibiotic prophylaxis in the form of 4-weekly benzathine penicillin injections is the mainstay of control programs. Evidence suggests, however, that delivery rates of such prophylaxis are poor.

METHODS

This qualitative study used semi-structured interviews with patients, parents/care givers and health professionals, to explore the enablers of and barriers to the uptake of secondary prophylaxis. Data from participant interviews (with 11 patients/carers and 11 health practitioners) conducted in four far north Queensland sites were analyzed using the method of constant comparative analysis.

RESULTS

Deficits in registration and recall systems and pain attributed to injections were identified as barriers to secondary prophylaxis uptake. There were also varying perceptions regarding responsibility for ensuring injection delivery. Enablers of secondary prophylaxis uptake included positive patient-healthcare provider relationships, supporting patient autonomy, education of patients, care givers and healthcare providers, and community-based service delivery.

CONCLUSION

The study findings provide insights that may facilitate enhancement of secondary prophylaxis delivery systems and thereby improve uptake of secondary prophylaxis for RF/RHD.

Comparison of approaches to rheumatic fever surveillance across Organisation for Economic Co-operation and Development countries

AIM

Rheumatic fever (RF) prevention, control and surveillance are increasingly important priorities in New Zealand (NZ) and Australia. We compared RF surveillance across Organisation for Economic Co-operation and Development (OECD) member countries to assist in benchmarking and identifying useful approaches.

METHODS

A structured literature review was completed using Medline and PubMed databases, investigating RF incidence rates. Surveillance methods were noted. Health department websites were searched to assess whether addressing RF was a Government priority.

RESULTS

Of 32 OECD member countries, nine reported RF incidence rates after 1999. Highest rates were seen in indigenous Australians, and NZ Māori and Pacific peoples. NZ and Australian surveillance systems are highly developed, with notification and register data compiled regularly. Only these two Governments appeared to prioritise RF surveillance and control. Other countries relied mainly on hospitalisation data. There is a lack of standardisation across incidence rate calculations. Israel and Italy may have relatively high RF rates among developed countries.

CONCLUSIONS

RF lingers in specific populations in OECD member countries. At a minimum, RF registers are needed in higher incidence countries. Countries with low RF incidences should periodically review surveillance information to ensure rates are not increasing.

Disparity in Mortality From Rheumatic Heart Disease in Indigenous Australians

Background

Recent estimates of the global burden of rheumatic heart disease (RHD) have highlighted the paucity of reliable RHD mortality data from populations most affected by RHD.

Methods and Results

We investigated RHD mortality rates and trends for Indigenous and non-Indigenous Australians in the Northern Territory (NT) for the period 1977–2005 and seminationally (NT plus 4 other states, covering 89% of Indigenous Australians) from 1997 to 2005 using vital statistics data. All analysis was undertaken by Indigenous status, sex, and age at death. In the NT, 90% of all deaths from RHD were among Indigenous persons; however, the Indigenous population makes up only 30.4% of the NT population. The death rate ratio (Indigenous compared with non-Indigenous) was 54.80 in the NT and 12.74 in the other 4 states (estimated at the median age of 50 years). Non-Indigenous death rates were low for all age groups except ≥65 years, indicating RHD deaths in the elderly non-Indigenous population. Death rates decreased at a more rapid rate for non-Indigenous than Indigenous persons in the NT between 1997 and 2005. Indigenous persons in other parts of Australia showed lower death rates than their NT counterparts, but the death rates for Indigenous persons in all states were still much higher than rates for non-Indigenous Australians.

Conclusions

Indigenous Australians are much more likely to die from RHD than other Australians. Among the Indigenous population, RHD mortality is much higher in the NT than elsewhere in Australia, exceeding levels reported in many industrialized countries more than a century ago. With the paucity of data from high-prevalence areas, these data contribute substantially to understanding the global burden of RHD mortality.

Echo-based screening of rheumatic heart disease in children: a cost-effectiveness Markov model

OBJECTIVES

To project the cost-effectiveness of population-based echo screening to prevent rheumatic heart disease (RHD) consequences.

BACKGROUND

RHD is a leading cause of cardiovascular mortality and morbidity during adolescence and young adulthood in low- and middle-per capita income settings. Echocardiography-based screening approaches can dramatically expand the number of children identified at risk of progressive RHD. Cost-effectiveness analysis can inform public health agencies and payers about the net economic benefit of such large-scale population-based screening.

METHODS

A Markov model was constructed comparing a no-screen to echo screen approach. The echo screen program was modeled as a 2-staged screen of a cohort of 11-year-old children with initial short screening performed by dedicated technicians and follow-up complete echo by cardiologists. Penicillin RHD prophylaxis was modeled to only reduce rheumatic fever recurrence-related exacerbation. Quality-adjusted life years (QALYs) and societal costs (in 2010 Australian dollars) associated with each approach were estimated. One-way, two-way and probabilistic sensitivity analyses were performed on RHD prevalence and transition probabilities; echocardiography test characteristics; and societal level costs including supplies, transportation, and labor.

RESULTS

The incremental costs and QALYs of the screen compared to no screen strategy were -$432 (95% CI = -$1357 to $575) and 0.007 (95% CI = -0.0101 to 0.0237), respectively. The joint probability that the screen was both less costly and more effective exceeded 80%. Sensitivity analyses suggested screen strategy dominance depends mostly on the probability of transitioning out of sub-clinical RHD.

CONCLUSION

Two-stage echo RHD screening and secondary prophylaxis may achieve modestly improved outcomes at lower cost compared to clinical detection and deserves closer attention from health policy stakeholders.

Improvement in rheumatic fever and rheumatic heart disease management and prevention using a health centre-based continuous quality improvement approach

BACKGROUND

Rheumatic heart disease (RHD) remains a major health concern for Aboriginal Australians. A key component of RHD control is prevention of recurrent acute rheumatic fever (ARF) using long-term secondary prophylaxis with intramuscular benzathine penicillin (BPG). This is the most important and cost-effective step in RHD control. However, there are significant challenges to effective implementation of secondary prophylaxis programs. This project aimed to increase understanding and improve quality of RHD care through development and implementation of a continuous quality improvement (CQI) strategy.

METHODS

We used a CQI strategy to promote implementation of national best-practice ARF/RHD management guidelines at primary health care level in Indigenous communities of the Northern Territory (NT), Australia, 2008-2010. Participatory action research methods were employed to identify system barriers to delivery of high quality care. This entailed facilitated discussion with primary care staff aided by a system assessment tool (SAT). Participants were encouraged to develop and implement strategies to overcome identified barriers, including better record-keeping, triage systems and strategies for patient follow-up. To assess performance, clinical records were audited at baseline, then annually for two years. Key performance indicators included proportion of people receiving adequate secondary prophylaxis (≥80% of scheduled 4-weekly penicillin injections) and quality of documentation.

RESULTS

Six health centres participated, servicing approximately 154 people with ARF/RHD. Improvements occurred in indicators of service delivery including proportion of people receiving ≥40% of their scheduled BPG (increasing from 81/116 [70%] at baseline to 84/103 [82%] in year three, p = 0.04), proportion of people reviewed by a doctor within the past two years (112/154 [73%] and 134/156 [86%], p = 0.003), and proportion of people who received influenza vaccination (57/154 [37%] to 86/156 [55%], p = 0.001). However, the proportion receiving ≥80% of scheduled BPG did not change. Documentation in medical files improved: ARF episode documentation increased from 31/55 (56%) to 50/62 (81%) (p = 0.004), and RHD risk category documentation from 87/154 (56%) to 103/145 (76%) (p < 0.001). Large differences in performance were noted between health centres, reflected to some extent in SAT scores.

CONCLUSIONS

A CQI process using a systems approach and participatory action research methodology can significantly improve delivery of ARF/RHD care.

The quality of health research for young Indigenous Australians: systematic review

OBJECTIVE

To assess the extent and quality of the evidence base related to the health and wellbeing of young Indigenous Australians.

STUDY DESIGN

Systematic review of peer-reviewed literature; grading of quality of literature; mapping of sample characteristics and study foci.

DATA SOURCES

English language publications, 1 Jan 1994 - 1 Jan 2011 in MEDLINE, ERIC, CINAHL, EMBASE, ATSIhealth, PsycINFO, the Cochrane Library and the Australian Indigenous HealthInfoNet.

STUDY SELECTION

Inclusion criteria were: published 1 Jan 1994 - 1 Jan 2011; original peer-reviewed research; reported data for Australian Aboriginal and Torres Strait Islanders aged 10-24 2013s; focused on health and wellbeing. Grading for quality included ascertainment of Indigenous status, representativeness of the sample for the target population, and quality of measures of exposure and outcome.

DATA SYNTHESIS

360 peer-reviewed publications met inclusion criteria; 90 (25%) exclusively sampled Indigenous young people. 250 studies (69%) were of good-quality design; 124 of these focused on health outcomes (15 of these evaluated an intervention) and 116 focused on health-risk exposure (26 evaluative). The methodological quality of data improved during 1994-2010; however, only 17% of studies focused on urban populations. A third of good-quality studies of health outcome focused on communicable diseases such as sexually transmitted infections and tuberculosis. There was good-quality data for oral health and substance use, and some data for adolescent pregnancy. Data on mental disorders, injury and cause-specific mortality were limited.

CONCLUSIONS

Despite improvements, there are important gaps in the evidence base for the health of young Indigenous Australians. Our study points to the need for greater research investment in urban settings and with regard to mental disorders and injury, with a further emphasis on trials of preventive and clinical intervention.

Cardiac surgery in Indigenous Australians--how wide is 'the gap'?

BACKGROUND

Cardiovascular disease remains the leading cause of mortality in the Indigenous Australian population. Limited research exists in regards to cardiac surgery in the Aboriginal and Torres Strait Islander (ATSI) population. We aimed to investigate risk profiles, surgical pathologies, surgical management and short term outcomes in a contemporary group of patients.

METHODS

Variables were assessed for 557 consecutive patients who underwent surgery at our institution between August 2008 and March 2010.

RESULTS

19.2% (107/557) of patients were of Indigenous origin. ATSI patients were significantly younger at time of surgery (mean age 54.1±13.23 vs. 63.1±12.46; p=<0.001) with higher rates of preventable risk factors. Rheumatic heart disease (RHD) was the dominant valvular pathology observed in the Indigenous population. Significantly higher rates of left ventricular impairment and more diffuse coronary artery disease were observed in ATSI patients. A non-significant trend towards higher 30-day mortality was observed in the Indigenous population (5.6% vs. 3.1%; p=0.244).

CONCLUSIONS

Cardiac surgery is generally required at a younger age in the Indigenous population with patients often presenting with more advanced disease. Despite often more advanced disease, surgical outcomes do not differ significantly from non-Indigenous patients. Continued focus on preventative strategies for coronary artery disease and RHD in the Indigenous population is required.

Screening for rheumatic heart disease in Aboriginal and Torres Strait Islander children

Rheumatic heart disease is preventable but causes significant morbidity and mortality in Aboriginal Australian and Torres Strait Islander populations. Screening echocardiography has the potential to detect early rheumatic heart disease thereby enabling timely commencement of treatment (secondary prophylaxis) to halt disease progression. However, a number of issues prevent echocardiographic screening for rheumatic heart disease satisfying the Australian criteria for acceptable screening programs. Primarily, it is unclear what criteria should be used to define a positive screening result as questions remain regarding the significance, natural history and potential treatment of early and subclinical rheumatic heart disease. Furthermore, at present the delivery of secondary prophylaxis in Australia remains suboptimal such that the potential benefits of screening would be limited. Finally, the impact of echocardiographic screening for rheumatic heart disease on local health services and the psychosocial health of patients and families are yet to be ascertained.

Acute rheumatic fever and rheumatic heart disease: incidence and progression in the Northern Territory of Australia, 1997 to 2010

BACKGROUND

Although acute rheumatic fever (ARF) and its sequel, rheumatic heart disease (RHD), continue to cause a large burden of morbidity and mortality in disadvantaged populations, most studies investigating the effectiveness of control programs date from the 1950s. A control program, including a disease register, in the Northern Territory of Australia where the Indigenous population has high rates of ARF and RHD allowed us to examine current disease incidence and progression.

METHODS AND RESULTS

ARF and RHD incidence rates, ARF recurrence rates, progression rates from ARF to RHD to heart failure, and RHD survival and mortality rates were calculated for Northern Territory residents from 1997 to 2010. For Indigenous people, ARF incidence was highest in the 5- to 14-year age group (males, 162 per 100,000; females, 228 per 100,000). There was little evidence that the incidence of ARF or RHD had declined. The ARF recurrence rate declined by 9% per year after diagnosis. After a first ARF diagnosis, 61% developed RHD within 10 years. After RHD diagnosis, 27% developed heart failure within 5 years. For Indigenous RHD patients, the relative survival rate was 88.4% at 10 years after diagnosis and the standardized mortality ratio was 1.56 (95% confidence interval, 1.23-1.96).

CONCLUSIONS

For Indigenous Australians in the Northern Territory, ARF and RHD incidence and associated mortality remain very high. The reduction in ARF recurrence indicates that the RHD control program has improved secondary prophylaxis; a decline in RHD incidence is expected to follow.

Rheumatic Fever Follow-Up Study (RhFFUS) protocol: a cohort study investigating the significance of minor echocardiographic abnormalities in Aboriginal Australian and Torres Strait Islander children

Background

In Australia, rheumatic heart disease (RHD) is almost exclusively restricted to Aboriginal Australian and Torres Strait Islander people with children being at highest risk. International criteria for echocardiographic diagnosis of RHD have been developed but the significance of minor heart valve abnormalities which do not reach these criteria remains unclear. The Rheumatic Fever Follow-Up Study (RhFFUS) aims to clarify this question in children and adolescents at high risk of RHD.

Methods/design

RhFFUS is a cohort study of Aboriginal and/or Torres Strait Islander children and adolescents aged 8–17 years residing in 32 remote Australian communities. Cases are people with non-specific heart valve abnormalities detected on prior screening echocardiography. Controls (two per case) are age, gender, community and ethnicity-matched to cases and had a prior normal screening echocardiogram. Participants will have echocardiography about 3 years after initial screening echocardiogram and enhanced surveillance for any history suggestive of acute rheumatic fever (ARF). It will then be determined if cases are at higher risk of (1) ARF or (2) developing progressive echocardiography-detected valve changes consistent with RHD.

The occurrence and timing of episodes of ARF will be assessed retrospectively for 5 years from the time of the RhFFUS echocardiogram. Episodes of ARF will be identified through regional surveillance and notification databases, carer/subject interviews, primary healthcare history reviews, and hospital separation diagnoses.

Progression of valvular abnormalities will be assessed prospectively using transthoracic echocardiography and standardized operating and reporting procedures. Progression of valve lesions will be determined by specialist cardiologist readers who will assess the initial screening and subsequent RhFFUS screening echocardiogram for each participant. The readers will be blinded to the initial assessment and temporal order of the two echocardiograms.

Discussion

RhFFUS will determine if subtle changes on echocardiography represent the earliest changes of RHD or mere variations of normal heart anatomy. In turn it will inform criteria to be used in determining whether secondary antibiotic prophylaxis should be utilized in individuals with no clear history of ARF and minor abnormalities on echocardiography. RhFFUS will also inform the ongoing debate regarding the potential role of screening echocardiography for the detection of RHD in this setting.

Screening for rheumatic heart disease: current approaches and controversies

Rheumatic heart disease (RHD) is a leading cause of cardiac disease among children in developing nations, and in indigenous populations of some industrialized countries. In endemic areas, RHD has long been a target of screening programmes that, historically, have relied on cardiac auscultation. The evolution of portable echocardiographic equipment has changed the face of screening for RHD over the past 5 years, with greatly improved sensitivity. However, concerns have been raised about the specificity of echocardiography, and the interpretation of minor abnormalities poses new challenges. The natural history of RHD in children with subclinical abnormalities detected by echocardiographic screening remains unknown, and long-term follow-up studies are needed to evaluate the significance of detecting these changes at an early stage. For a disease to be deemed suitable for screening from a public health perspective, it needs to fulfil a number of criteria. RHD meets some, but not all, of these criteria. If screening programmes are to identify additional cases of RHD, parallel improvements in the systems that deliver secondary prophylaxis are essential.

Heart failure among Indigenous Australians: a systematic review

Background

Cardiovascular diseases contribute substantially to the poor health and reduced life expectancy of Indigenous Australians. Heart failure is a common, disabling, progressive and costly complication of these disorders. The epidemiology of heart failure and the adequacy of relevant health service provision in Indigenous Australians are not well delineated.

Methods

A systematic search of the electronic databases PubMed, Embase, Web of Science, Cinahl Plus, Informit and Google Scholar was undertaken in April 2012 for peer-reviewed journal articles relevant to the topic of heart failure in Indigenous Australians. Additionally, a website search was done to identify other pertinent publications, particularly government reports.

Results

There was a paucity of relevant peer-reviewed research, and government reports dominated the results. Ten journal articles, 1 published conference abstract and 10 reports were eligible for inclusion. Indigenous Australians reportedly have higher morbidity and mortality from heart failure than their non-Indigenous counterparts (age-standardised prevalence ratio 1.7; age-standardised hospital separation ratio ≥3; crude per capita hospital expenditure ratio 1.58; age-adjusted mortality ratio >2). Despite the evident disproportionate burden of heart failure in Indigenous Australians, the accuracy of estimation from administrative data is limited by poor indigenous identification, inadequate case ascertainment and exclusion of younger subjects from mortality statistics. A recent journal article specifically documented a high prevalence of heart failure in Central Australian Aboriginal adults (5.3%), noting frequent undiagnosed disease. One study examined barriers to health service provision for Indigenous Australians in the context of heart failure.

Conclusions

Despite the shortcomings of available published data, it is clear that Indigenous Australians have an excess burden of heart failure. Emerging data suggest that undiagnosed cases may be common in this population. In order to optimise management and to inform policy, high quality research on heart failure in Indigenous Australians is required to delineate accurate epidemiological indicators and to appraise health service provision.

Rheumatic heart disease

Rheumatic heart disease, often neglected by media and policy makers, is a major burden in developing countries where it causes most of the cardiovascular morbidity and mortality in young people, leading to about 250,000 deaths per year worldwide. The disease results from an abnormal autoimmune response to a group A streptococcal infection in a genetically susceptible host. Acute rheumatic fever--the precursor to rheumatic heart disease--can affect different organs and lead to irreversible valve damage and heart failure. Although penicillin is effective in the prevention of the disease, treatment of advanced stages uses up a vast amount of resources, which makes disease management especially challenging in emerging nations. Guidelines have therefore emphasised antibiotic prophylaxis against recurrent episodes of acute rheumatic fever, which seems feasible and cost effective. Early detection and targeted treatment might be possible if populations at risk for rheumatic heart disease in endemic areas are screened. In this setting, active surveillance with echocardiography-based screening might become very important.

Group a streptococcal diseases and their global burden

Group A streptococcus (GAS) or Streptococcus pyogenes has been recognised as an important human pathogen since early days of modern microbiology, and it remains among the top ten causes of mortality from an infectious disease. Clinical manifestations attributable to this organism are perhaps the most diverse of any single human pathogen. These encompass invasive GAS infections, with high mortality rates despite effective antimicrobials, toxin-mediated diseases including scarlet fever and streptococcal toxic shock syndrome, the autoimmune sequelae of rheumatic fever and glomerulonephritis with potential for long-term disability, and nuisance manifestations of superficial skin and pharyngeal infection, which continue to consume a sizable proportion of healthcare resources. Although an historical perspective indicates major overall reductions in GAS infection rates in the modern era, chiefly as a result of widespread improvements in socioeconomic circumstances, this pathogen remains as a leading infectious cause of global morbidity and mortality. More than 18 million people globally are estimated to suffer from serious GAS disease. This burden disproportionally affects least affluent populations, and is a major cause of illness and death among children and young adults, including pregnant women, in low-resource settings. We review GAS transmission characteristics and prevention strategies, historical and geographical trends and report on the estimated global burden disease attributable to GAS. The lack of systematic reporting makes accurate estimation of rates difficult. This highlights the need to support improved surveillance and epidemiological research in low-resource settings, in order to enable better assessment of national and global disease burdens, target control strategies appropriately and assess the success of control interventions.

Disease appearance and evolution against a background of climate change and reduced resources

Global health continues to face increasing challenges owing to a variety of reasons that include the almost constant changes in disease appearance and evolution. Most, but not all, of these changes affect low-income countries and are influenced by climate change. Tracking the recent and anticipated changes in the demographics and global distribution of these changes is essential for evolving effective new methods for dealing with the problems. The recent recognition by the United Nations of the importance of non-communicable diseases is a major positive step. For the sake of this paper, the following diseases were chosen: dengue and malaria, to highlight the role of climate change on vector-borne diseases. Drug-resistant tuberculosis illustrates the role of globalization and reduced resources on disease evolution. The continuing rise in cardiovascular mortality and morbidity, particularly in resource-poor countries is largely attributed to lack of preventive and therapeutic measures against such conditions as hypertension, diabetes, atherosclerosis and congenital heart disease as well as neglected diseases, of which Chagas and rheumatic heart disease will be discussed further.

Underdiagnosis of acute rheumatic fever in primary care settings in a developing country

OBJECTIVES

To determine the incidence rate, characterize the clinical features and assess the diagnostic evaluation of children presenting with features of acute rheumatic fever (ARF) at two clinics in a region of Fiji where rheumatic heart disease is known to be endemic.

METHODS

We reviewed 5 years (2003-2008) of primary care records from 15 841 patients aged 4-20 years using a pre-determined case definition for ARF; and we reviewed detailed clinical data from 944 cases with features of possible ARF.

RESULTS

The crude incidence of first episodes of definite ARF in this setting among patients aged 4-20 years was 24.9 per 100 000 person-years. Joint involvement suggestive of a potential first presentation of ARF but not sufficient for a definite retrospective diagnosis was documented in a further 94 records. There were another 514 cases of joint involvement less suggestive of ARF and 316 cases of unexplained fever with no evidence of localized infection. Patients presenting with potential features of ARF seldom had a diagnostic evaluation sufficient to exclude its diagnosis.

CONCLUSIONS

The incidence of ARF at these clinics is nearly twice that reported in a local hospital-based study, but it is likely to under-represent the actual number of cases presenting to primary care. There is a need for better surveillance for ARF and to develop simple and practical approaches to diagnosing ARF in primary care in low-resource settings.

First-episode versus recurrent acute rheumatic fever: is it different?

BACKGROUND

Recurrent episodes of acute rheumatic fever (RF) can lead to rheumatic heart disease with considerable disability and mortality in children. RF can recur in the absence of secondary prophylaxis. The differences in clinical manifestations and outcome between first-episode and recurrent RF have been less studied.

METHODS

A cross-section of patients under 14 years was studied for 2 years (2003-2005) in order to compare the clinical, laboratory, echocardiographic profile and outcome of first-episode RF with recurrent attacks, and risk factors for recurrence and mortality. Patients without a previous history of RF and/or mitral stenosis (MS) and/or aortic stenosis (AS) were defined as first-episode patients, and patients with previous history of RF and/or MS and/or AS, were defined as recurrent RF patients based on the Jones criteria.

RESULTS

Of 51 patients in total, 26 had first-episode RF and 25 had recurrent RF. Arthritis occurred in a significantly higher number of first-episode patients (P = 0.047) whereas shortness of breath (SOB; P = 0.003), palpitation (P = 0.034), and aortic regurgitation (AR; P = 0.001) occurred in a significantly higher number of recurrent RF patients. Audible murmur of corresponding echocardiographic regurgitation was present in all recurrent RF patients whereas audible murmur was present in 61.5% and echocardiographic regurgitation in 81% in first-episode patients (P = 0.007). Palpitation, SOB, audible murmur, thrill, age and AR on admission were independent predictors of recurrence. Palpitation, age and AS on admission were independent predictors of mortality.

CONCLUSIONS

Subclinical carditis occurred only in the first-episode patients, which requires further evaluation for clinical significance. Because all deaths occurred in recurrent RF group (P = 0.02), secondary prophylaxis and management of sore throat need re-emphasis.

Variation in clinical presentation of childhood group A streptococcal pharyngitis in four countries

We conducted a cross-sectional study from September 2001 to August 2003 during which children between 2 and 12 years of age presenting with complaint of sore throat were recruited from urban pediatric clinics in Brazil, Croatia, Egypt and Latvia. The objective of the study was to compare clinical signs and symptoms of children presenting to urban pediatric clinics with sore throat in and between countries and to identify common clinical criteria predicting group A beta hemolytic streptococcal (GAS) pharyngitis. Using a single standard protocol in all four sites, clinical data were recorded and throat swabs obtained for standard GAS culture in 2040 children. Signs and symptoms were tested for statistical association with GAS positive/negative pharyngitis, and were compared using chi(2) tests, ANOVA and Odds Ratios. Clinical signs of GAS pharyngitis in children presenting to clinics varied significantly between countries, and there were few signs or symptom that could statistically be associated with GAS pharyngitis in all four countries, though several were useful in two or three countries. Our results indicate that the clinical manifestations of pharyngitis in clinics may vary by region. It is therefore critical that clinical decision rules for management of pharyngitis should have local validation.

Percutaneous balloon mitral commissurotomy in indigenous versus non-indigenous Australians

BACKGROUND

Rheumatic heart disease remains a serious health issue amongst the Australian indigenous population. Percutaneous balloon mitral commissurotomy (PBMC) has become the treatment of choice in patients with symptomatic pure mitral stenosis with favourable valve morphology. There is little published data on the efficacy of PBMC in indigenous Australians.

AIMS

We sought to document differences between indigenous Australians (IA) and non-indigenous Australians (NIA) undergoing percutaneous balloon mitral commissurotomy (PBMC) at The Prince Charles Hospital and Holy Spirit Northside Hospital from 1990 to 2006.

METHODS

PBMC was performed in 327 patients using the Inoue-balloon technique (271 female, 56 male, age +/-15 years (mean+/-S.D.), (range 13-89) between March 1990 and March 2006.

RESULTS

The IA population was over represented in this cohort (11% versus an estimated 3.4% of the Queensland population) and comprised the largest non-Caucasian group. Compared with the NIA population they were younger (mean age 36 years (+/-13) versus mean 52(+/-14) years (P<0.05)). Baseline mitral valve area (MVA) was similar in the IA and NIA groups (0.96 cm(2) versus 1.08 cm(2)P=0.9). Mitral valve Echo-score was also similar between the two groups (mean score 7.36 versus 7.52 P=0.8). The IA population had higher pre-procedural mitral valve gradients (14.3 mmHg versus 11.1 mmHg, P<0.05), but less mitral valve calcification. Procedural success was achieved in 91% of both groups. Post procedural MVA (planimetry) was similar (1.98 cm(2) versus 1.84 cm(2)P=0.6), as was percent reduction in mitral valve gradient. Inadequate dilatation was seen in 1 (3%) IA and in 10 (3.6%) of the NIA group. Significant MR was seen in 2 (6%) IA patients and 11 (4%) NIA patients. There were no deaths or strokes or pericardiocenteses in either group.

CONCLUSION

The indigenous population makes up a significant proportion of patients requiring PBMC in Queensland. They present younger and with higher mitral valve gradients. The procedure is safe in both the indigenous and non-indigenous Australian population. Further research is required to establish the long-term efficacy of this procedure in indigenous Australians.

The high burden of rheumatic heart disease found on autopsy in Fiji

Rheumatic heart disease causes more than 200,000 deaths worldwide annually, with the vast majority of these deaths occurring in developing countries, yet there are few autopsy studies of rheumatic heart disease in these countries. We performed a retrospective review of 6218 autopsies performed during the period from 1990 through 2006, searching for cases of rheumatic heart disease based upon the macroscopic pathologic examination of the heart. We found 147 cases (2.4%) of rheumatic heart disease. There was an apparent increase in the number of cases in the past 5 years. There were 95 deaths that were directly attributable to rheumatic heart disease, with congestive cardiac failure being the most common cause of death in 75 cases. The mean age at death due to rheumatic heart disease was 38 years. There were more cases of rheumatic heart disease in Indigenous Fijians than Indo-Fijians, with an adjusted relative risk of 1.26 (95% confidence intervals from 0.87 to 1.86). Our findings reflect the high burden and early age of death due to rheumatic heart disease in Fiji and the Pacific region generally, and underline the need for early detection and adequate secondary penicillin prophylaxis in this region.

Acute rheumatic fever: adherence to secondary prophylaxis and follow up of Indigenous patients in the Katherine region of the Northern Territory

OBJECTIVE

This paper evaluates adherence with secondary preventative treatment and follow up of acute rheumatic fever (ARF) within the Katherine region of the Northern Territory after the introduction of an ARF register. We aimed to assess the rate of adherence with penicillin prophylaxis and follow-up guidelines in patients with previous ARF and the effect of factors such as age, sex, disease severity and clinic attendance.

DESIGN

Retrospective study.

SETTING

Five Indigenous Community Health Centres located in the Katherine region of the Northern Territory, Australia.

PARTICIPANTS

Fifty-nine people resident in five communities who were prescribed monthly prophylactic penicillin for ARF during the 24 months between September 2002 and September 2004. All subjects were Indigenous.

MAIN OUTCOME MEASURE

Main outcome measures were the number of penicillin injections received over the 24-month period and frequency of echocardiogram and specialist follow up in comparison to Rheumatic Fever Registry Guidelines.

RESULTS

Mean adherence with prophylaxis was 56% of prescribed doses. A non-significant trend towards improved adherence was seen in children, patients with less severe disease and those who attended the clinic more frequently. Rheumatic Fever Registry Guidelines for echocardiogram and specialist review were met by 63% and 59% of subjects, respectively.

CONCLUSION

Within this population adherence with penicillin prophylaxis is inadequate to protect against recurrence of ARF and consequent worsening of rheumatic heart disease. In addition, the Rheumatic Fever Registry Guidelines for specialist follow up and echocardiogram are not being adhered to for many patients.

Use of the Jones Criteria in the diagnosis of acute rheumatic fever in an Australian rural setting

OBJECTIVE

To answer the question, are the Jones Criteria being used appropriately in the diagnosis of acute rheumatic fever (ARF) by non-specialist medical staff in a remote Australian setting?

METHODS

The medical records of all patients discharged from Katherine Hospital (Northern Territory) with a diagnosis of ARF between January 2000 and April 2004 were retrospectively reviewed for adherence to the Jones Criteria. Data were also collected on specialist follow-up and need for transfer to a tertiary hospital.

RESULTS

Twenty-five patients had a diagnosis of ARF and all were Aboriginal or Torres Strait Islander. Thirty-two per cent did not fulfil the Jones Criteria and of these 63% were recurrent cases. Eighty-eight per cent received specialist follow-up and of those who did not fulfil the Jones Criteria, all were diagnosed as ARF by the specialist. Only 20% required transfer to a tertiary hospital for higher-level care.

CONCLUSION

The Jones Criteria are being used appropriately to diagnose initial episodes of ARF but less successfully in recurrent episodes. Specialist follow-up is essential but acute episodes can be managed in remote settings, reducing the need to transfer patients to tertiary care with resultant patient dislocation and social isolation.

IMPLICATIONS

The diagnosis of ARF results in long-term penicillin prophylaxis. This is a major public health undertaking that requires correct diagnosis. This study demonstrates that the Jones Criteria are being used appropriately to diagnose ARF in a remote setting. The ability to diagnose and treat Indigenous patients within their local region reduces social isolation and creates a more positive health care experience.

Rheumatic fever and social justice

High rates of this disease are the face of Indigenous disadvantage.

Experience with cardiac valve operations in Cape York Peninsula and the Torres Strait Islands, Australia

OBJECTIVE

To describe the outcome of valve surgery, for rheumatic heart disease (RHD) and non-RHD, in residents of Cape York Peninsula and the Torres Strait Islands referred to the Cairns Base Hospital specialist outreach service.

DESIGN AND PARTICIPANTS

Retrospective review of medical records on all patients residing in the outreach area who had surgery for valvular heart disease between 1 January 1992 and 31 December 2004.

MAIN OUTCOME MEASURES

Operation type and perioperative characteristics; 5- and 10-year survival rates; reoperation rates; complications.

RESULTS

Forty-seven patients met the selection criteria; the median age was 40 years (range, 4-76 years); and 39 patients were Indigenous. RHD was the predominant cause of valve dysfunction (30/47 patients). Thirty-seven patients had valve replacements, six had valve repair and four had balloon valvotomy as the initial procedure. There were three bleeding complications, two episodes of operated valve endocarditis, and six embolic complications. There were nine valve-related deaths (six in the first 5 years). At 5 years, all seven patients who had had valve repair or balloon valvotomy were alive. Seven of the 47 patients required reoperation. Survival analysis showed freedom from valve-related deaths to be 83% (95% CI, 66%-92%) at 5 years and 61% (95% CI, 33%-80%) at 10 years. Freedom from reoperation at 5 years was 88% (95% CI, 71%-95%). Among the 30 patients with RHD, freedom from valve-related death was 80% (95% CI, 60%-92%) at 5 years and 52% (95% CI, 21%-75%) at 10 years. In patients with RHD, freedom from reoperation at 5 years was 87% (95% CI, 65%-96%).

CONCLUSION

Valvular heart disease results in substantial morbidity and mortality, despite intervention. Efforts need to focus on prevention of rheumatic fever and closer follow-up.

The Challenge of Acute Rheumatic Fever Diagnosis in a High-Incidence Population: A Prospective Study and Proposed Guidelines for Diagnosis in Australia's Northern Territory

BACKGROUND

Accurate diagnosis of acute rheumatic fever (ARF) remains problematic in high-incidence settings and especially in the Aboriginal population of Australia's Northern Territory. Previous investigators have demonstrated that strict application of the 1992 Updated Jones Criteria results in under-diagnosis. This study's objectives were to review use of the Jones Criteria (1992 Update) in diagnosing ARF in Australian Aboriginal patients presenting with suspected rheumatic fever, and formulate a locally relevant algorithm to improve diagnosis.

METHODS

Patients presenting to Royal Darwin Hospital with suspected ARF were prospectively assessed during a 15-month period. Demographic information, clinical history, examination, laboratory and echocardiographic findings were documented in order to determine whether the Jones Criteria were fulfilled, and to identify alternative diagnoses. The hospital discharge diagnosis was recorded and patients were followed up 18-33 months later.

RESULTS

Out of 35 patients with suspected ARF, all were Aboriginal Australians, 17 (49%) had a discharge diagnosis of definite ARF, 7 (20%) had definite non-rheumatic fever diagnoses (disseminated gonococcal infection, systemic lupus erythematosis, buttock abscess and other febrile illnesses in children with cardiac murmur due to previously undiagnosed RHD). The remaining 11 (31%) posed diagnostic difficulties because of mild symptoms that failed to fulfil Jones Criteria (attracting diagnoses such as 'unexplained arthralgia') or atypical features such as older age. Two patients whose illness initially failed to fulfil the Jones Criteria, who were neither diagnosed with ARF nor commenced on secondary benzathine penicillin prophylaxis, were found on follow-up to have definite and probable ARF, respectively. At least 29% (8/28) of patients without prior recognised ARF/RHD had echocardiographic evidence of established RHD, indicating that previous episodes were missed.

CONCLUSIONS

Individual mild episodes of ARF may be overlooked, with patients missing out on the timely institution of secondary prophylaxis. The Jones Criteria should be supplemented by active exclusion of differential diagnoses and vigilant follow-up including echocardiography. 'Probable' and 'possible ARF' should be recognised as diagnostic categories applying to patients not fulfilling the Jones Criteria but who nevertheless should be offered prophylactic penicillin at least until further follow-up. A set of diagnostic guidelines is proposed.

The global burden of group A streptococcal diseases

The global burden of disease caused by group A streptococcus (GAS) is not known. We review recent population-based data to estimate the burden of GAS diseases and highlight deficiencies in the available data. We estimate that there are at least 517,000 deaths each year due to severe GAS diseases (eg, acute rheumatic fever, rheumatic heart disease, post-streptococcal glomerulonephritis, and invasive infections). The prevalence of severe GAS disease is at least 18.1 million cases, with 1.78 million new cases each year. The greatest burden is due to rheumatic heart disease, with a prevalence of at least 15.6 million cases, with 282,000 new cases and 233,000 deaths each year. The burden of invasive GAS diseases is unexpectedly high, with at least 663,000 new cases and 163,000 deaths each year. In addition, there are more than 111 million prevalent cases of GAS pyoderma, and over 616 million incident cases per year of GAS pharyngitis. Epidemiological data from developing countries for most diseases is poor. On a global scale, GAS is an important cause of morbidity and mortality. These data emphasise the need to reinforce current control strategies, develop new primary prevention strategies, and collect better data from developing countries.

Acute rheumatic fever: a chink in the chain that links the heart to the throat?

Acute rheumatic fever (ARF) remains a major problem in tropical regions, resource-poor countries, and minority indigenous communities. It has long been thought that group A streptococcal (GAS) pharyngitis alone was responsible for acute rheumatic fever; this belief has been supported by laboratory and epidemiological evidence gathered over more than 60 years, mainly in temperate climates where GAS skin infection is uncommon. GAS strains have been characterised as either rheumatogenic or nephritogenic based on phenotypic and genotypic properties. Primary prevention strategies and vaccine development have long been based on these concepts. The epidemiology of ARF in Aboriginal communities of central and northern Australia challenges this view with reported rates of ARF and rheumatic heart disease (RHD) that are among the highest in the world. GAS throat colonisation is uncommon, however, and symptomatic GAS pharyngitis is rare; pyoderma is the major manifestation of GAS infection. Typical rheumatogenic strains do not occur. Moreover, group C and G streptococci have been shown to exchange key virulence determinants with GAS and are more commonly isolated from the throats of Aboriginal children. We suggest that GAS pyoderma and/or non-GAS infections are driving forces behind ARF in these communities and other high-incidence settings. The question needs to be resolved as a matter of urgency because current approaches to controlling ARF/RHD in Aboriginal communities have clearly been ineffective. New understanding of the pathogenesis of ARF would have an immediate effect on primary prevention strategies and vaccine development.

The epidemiology of childhood cardiomyopathy in Australia

BACKGROUND

The incidence and age distribution of primary cardiomyopathy in children are not well defined. We undertook a population-based, retrospective cohort study in Australia to document the epidemiology of childhood cardiomyopathy.

METHODS

We analyzed all cases of primary cardiomyopathy in children who presented between 1987 and 1996 and who were younger than 10 years of age. Children were recruited from multiple sources, and cases of cardiomyopathy were classified according to World Health Organization guidelines.

RESULTS

Over the 10-year period, 314 new cases of primary cardiomyopathy were identified, for an annual incidence of 1.24 per 100,000 children younger than 10 years of age (95 percent confidence interval, 1.11 to 1.38). Dilated cardiomyopathy made up 58.6 percent of cases, hypertrophic cardiomyopathy 25.5 percent, restrictive cardiomyopathy 2.5 percent, and left ventricular noncompaction 9.2 percent of cases. The incidence of all types of cardiomyopathy except restrictive declined rapidly after infancy. In 11 cases (3.5 percent), sudden death was the first symptom. There was a male predominance among children with hypertrophic and unclassified cardiomyopathy. Indigenous children had a higher incidence of dilated cardiomyopathy than nonindigenous children (relative risk, 2.67; 95 percent confidence interval, 1.42 to 4.63) and a higher rate of death as the presenting symptom (16.7 percent vs. 2.6 percent, P=0.02). Lymphocytic myocarditis was present in 25 of 62 children with dilated cardiomyopathy (40.3 percent) who underwent cardiac histologic examination within two months after presentation.

CONCLUSIONS

Lymphocytic myocarditis and left ventricular noncompaction are important causes of childhood cardiomyopathy in Australia. The timing and severity of presentation in children with cardiomyopathy are related to the type of cardiomyopathy, as well as to genetic and ethnic factors.

A critical assessment of published guidelines and other decision-support systems for the antibiotic treatment of community-acquired respiratory tract infections

Guidelines are an important means by which professional associations and governments have sought to improve the quality and cost-effectiveness of disease management for infectious diseases. Prescribing of initial antibiotic therapy for community-acquired respiratory tract infections (RTIs) is primarily empiric and physicians may often have a limited appreciation of bacterial resistance. Recent guidelines for managing RTIs have adopted a more evidence-based approach. This process has highlighted important gaps in the existing knowledge base, e.g. concerning the impact of resistance on the effectiveness of oral antibiotics for outpatient community-acquired pneumonia and the level of resistance that should prompt a change in empiric prescribing. In upper RTIs, the challenge is to identify patients in whom antibiotic therapy is warranted. Concentrated, sustained efforts are needed to secure physicians' use of guidelines. The information should be distilled into a simple format available at the point of prescribing and supported by other behavioral change techniques (e.g. educational outreach visits). Advances in information technology offer the promise of more dynamic, computer-assisted forms of guidance. Thus, RTI prescribing guidelines and other prescribing support systems should help control bacterial resistance in the community. However, their effect on resistance patterns is largely unknown and there is an urgent need for collaborative research in this area. Rapid, cost-effective diagnostic techniques are also required and new antibiotics will continue to have a role in disease management.